Metazoan parasites of Geophagus brasiliensis (Perciformes: Cichlidae) in Patos lagoon, extreme south of Brazil

Abstract

This study has evaluated the parasitic fauna of 79 pearl cichlids (Geophagus brasiliensis) from the estuary of Patos Lagoon (31° 57' S and 52° 06' W), Rio Grande do Sul, Brazil, during the months of May and June in 2011 and 2012. All the hosts analyzed were infected with at least one species of parasite. A total of eleven metazoa were identified in 459 specimens collected. The trematode Austrodiplostomum compactum (34.2%) and ergasilids Ergasilus lizae (32.9%) and Gauchergasilus lizae (32.9%) were the most prevalent species. The trematodes Thometrema overstreeti and Posthodiplostomum sp. had significantly higher prevalence in fish longer than 20 cm. The sex of the host had no effect on parasite prevalence and abundance. Pearl cichlids are registered as a new host for the trematodes Lobatostoma sp., Homalometron pseudopallidum and Thometrema overstreeti, for the ergasilids Ergasilus lizae and Gauchergasilus euripedesi and for the argulid Argulus spinolosus. The crustacean E. lizae is recorded in Rio Grande do Sul for the first time.

Gauchergasilus euripedesi (Copepoda, Ergasilidae) parasitizing different species of fish from two environments in southern Brazil

“…The parameters of infestations of G. euripedesi available are presented in Table 1. In general, parameters of the host species examined in the present study are more similar to those reported for M. furnieri (Velloso and Pereira Jr. 2010), but smaller than those found in G. brasiliensis (Rassier et al 2015). These differences do not seem to be related to the number of hosts examined, since the two most sampled hosts (M. furnieri, n = 94 and G. brasiliensis, n = 79) presented differences between them.…”

“…Later, redescription of females and corrected description of males, were based on plankton samples collected in the estuarine area of Patos Lagoon (Montú and Boxshall 2002). In addition, females of G. euripedesi were found in M. furnieri by Velloso and Pereira Jr. (2010) in the pre-limnic region of the Patos Lagoon estuary, and in Geophagus brasiliensis (Quoy & Gaimard, 1824) by Rassier et al (2015) also in the estuarine area of Patos Lagoon. Araujo and Boxshall (2001) reported G. euripedesi obtained from plankton samples collected in the Piauí River estuary.…”

Fish parasites as indicators of organic pollution in southern Brazil

“…Only one specimen of the digenean Homalometron pseudopallidum was observed in our study. This parasite species was recorded for the same host from Patos Lagoon, Rio Grande do Sul, Brazil, by Rassier et al (2015), also presenting low values of prevalence (2.7%) and mean abundance (0.12).…”

“…There are several studies on the parasitic fauna of G. brasiliensis ; according to Eiras et al (2010), more than 30 species of parasite have been described for this host. Regarding studies on parasite ecology, we highlight the work of Azevedo et al (2006), Madi & Ueta (2009), Bellay et al (2012) and Rassier et al (2015). Madi & Ueta (2009) point to the monogenean subfamily Ancyrocephalinae as indicators of environmental quality in reservoirs of the State of São Paulo.…”

Occurrence of metacercariae of Austrodiplostomum compactum (Lutz, 1928) (Trematoda, Diplostomidae) in Pimelodus platicirris in the Ilha Solteira Reservoir, São Paulo, Brazil

“…The cercariae subsequently leave the snails and may remain encysted in vegetation or actively penetrate their second intermediate host (fish), commonly by the gills, reaching the eyes, brain and/or muscles through the bloodstream, where they develop into metacercariae. Finally, piscivorous birds prey the infected fish, giving continuity to the cycle (Thatcher 2006, Rassier et al 2015.…”